Use long --disable instead of short -q in curl

[vitorgalvao]

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Commands should use long flags instead of short flags when available. It makes it quicker to understand and detect errors.

[MikeMcQuaid]

Looks good! Could you also update

brew/Library/Homebrew/manpages/brew.1.md.erb

Lines 162 to 164 in 8f6029f

	* `HOMEBREW_CURLRC`:
	If set, Homebrew will not pass `-q` when invoking `curl`(1), which disables
	the use of `curlrc`.

and run brew man?

[vitorgalvao]

Done.

[MikeMcQuaid]

Good call, thanks @vitorgalvao!